Casing cementing back pressure valve and its operation



Oct. 6, 1959 G. S. ORMSBY Filed Oct. '7. 1954 Y'IIIIIIII 'lil/191111 2,907,392 cAsING CEMENTING BACK PRESSURE VALVE AND ITS OPERATION v IN V EN TOR.

GEORGE S. ORMSBY CASING CEMENTING BACK PRESSURE VALVE AND ITS OPERATION George S. Orinsby, Houston, Tex., assigner to Phillips Petroleum Company, a corporation of Delaware Application October 7, 1954, Serial No. 460,930 1 '15 Claims. (Cl. 166-224) This invention relates to a deep well casing bottom fill and back pressure valve assembly and its use in deep well casing running and cementing operations wherein the valve is actuated by a casing cementing plug. In one aspect it relates to a back pressure check valve for use in deep well cementing operations with the valve being actuated when a casing cementing plug is bottomed against the valve assembly. In another aspect it relates to a back pressure valve for use in deep well cementing operations wherein the valve is actuated as a cementing plug, forced down a casing, reaches the valve assembly as in conventional deep well cementing operations.

To complete an oil or gas well many operators prefer to install a float shoe or float collar at or near the bottom of the casing. Such a shoe or collar contains a check valve which allows downward ilow of uid through the pipe but prevents back-flow. Although such a device has certain advantages there are also very serious disadvantages, particularly in certain areas and fields. When using a float valve one disadvantage is that it is necessary to interrupt the casing running process periodically to fill the casing with drilling fluid from above toprevent gcollapse of the pipe due to the weight of the uid in the annulus because there is no fluid in the pipe for pressure balance. The loss of time occasioned by such lling operations is in itself a disadvantage but it is not as serious as the di'iculty with stuck casing which in certain areas is likely to occur when the casing running process is interrupted for more than short intervals of time.

Another serious disadvantage to the use of conventional float valves is the large pressure build-up which occurs opposite the lower end of the casing due to the drilling fluid displaced by the casing being forced upward through the annulus between the casing and the walls of the well. In many cases this pressure build-up results in the breakdown of permeable sections of earth formation and loss of drilling lluid, thus increasing the danger of a blow out.

Even if a blow out does not occur the formation may continue to take drilling uid after the cementing operation begins and thus may prevent the cement from rising to the desired height outside of the casing.

Another disadvantage of filling the casing from the top is that air is often entrained in the mud.

Certain bottom fill devices now on the market have been, and can be, inadvertently operated prematurely by the pressure surges and waves set up either when the casing is picked upward suddenly or when the downward movement of the casing is arrested too quickly. My invention permits casing movement of lany magnitude, direction and frequency, purposeful or accidental, at any time or times during the running operation, without actuating the back pressure valve and without affecting later actuation of the back pressure valve during the cementing operation. The actuation of my valve is alsok independent of uid ow through the valve, that is, fluid can ilow .upward and can ilow downward through the valve without releasing the valve to a seating position.

Attempts have been made to solve these problems Yby using pressure controlled valves which allow filling of the casing from the bottom but such valves have not been completely satisfactory.

When a casing is run completely open and is nearly as large as the hole, i.e. the annulus between the casing land the walls of the Well is smaller in cross section than the casing, the displaced drilling fluid will ilow up through the casing and overflow on the drilling rig floor.

According to my invention I have devised a check valve for use in conjunction with mud flow constrictors with the check valve being placed into operation by bottoming a cementing plug against the valve asesmbly.

lt is an advantage of my invention that the casing running operation can be discontinued and the mud circulated as often as necessary or desired without losing bottom kfill action. My invention permits alternately running casing with bottom till and stopping to circulate the hole, the time and frequency of such alternation being at the will of the operator, without actuating the back pressure valve and in no way affecting later actuation of the back pressure valve during the cementing operation.

An object of my invention is to provide a check valve for use in deep well cementing operations with the valve being placed into operation during a conventional cementing operation.

Another object of my invention isto provide a check valve for use in deep well cementing operations with the Valve being set to'operate by bottoming a cementing plug against the valve'assembly.

Still another object of my invention is to provide a check Valve for use in deep well cementing operations with the valve being used in conjunction with mud ow constrictors during running of the casing.

Yet another object of my invention is to devise such .a check valve that when said casing is bottomed the check valve is placed into operationduring cementing operations to prevent back flow of cement.

Still another object of my invention is to provide a check Valve for use in deep well cementing operations which involves lowering down the casing only apparatus ordinarily used in cementing operations.

Still other objects and advantages of my invention will be obvious to those skilled in the art upon reading the following specification and drawing which respectively describes and illustrates a` preferred embodiments of my invention.

In the drawing:

Figure l illustrates in diagrammatic form an elevationalview, partly in section, of one embodiment of my invention.

Figure 2 illustrates in diagrammatic form an elevational sectional view of a piece of apparatus to be used in conjunction With a portion of the apparatus of Figure l.

Figure 3 is an elevational view of a portion of the apparatusof Figure l.

Figure 4 is a plan view looking upward of aiportionof the apparatus of Figure 1.

v Figure 5 is a side view of the apparatus of Figure 4.

Figures 6, 7, 8 and l0 are elevational views, partly in section, of other embodiments of my invention.

Figure 9 is an elevational view,partly in section, of a portion of the apparatus of Figures 8 and l0 with additional elements. v

vFigure' ll is a sectional elevational view of apparatus parts illustrating a method of operating my apparatus.

Figure 12 illustrates an alternate formof a portionkof the apparatus of Figurel.

YAccording to my invention I' provide a cheek valve for use in deep well cementing operations which is placed into operative position bybottoming a well plug against the check valve apparatus by fluid pressure from the well head and this bottoming of the plug sets into operation a mechanical linkage or permits pressure build-up in a bypass to a valve actuating mechanism lower down the casing.

Referring now to the drawing and specifically to Figure l, this apparatus consists of a relatively short casing segment 21 which serves as a housing and support for the valve. A baille plug 25 is attached to the casing segment 21 by threads 36. This baille plug can be attached to the casing segment by any other suitable means desired, for example, it can be held in place by an upper ring and a lower ring or it can be welded into place in case it is made of metal. This baille plug is provided with a port 29, which is a cylindrical opening disposed axially throughout the length of the baille. The lower end of port 29 is bevelled to provide a seat 30 for 'an orifice holder 31. This orifice holder 31 is attached to a support element 45 by a spring loaded hinge 46. Support element 45 is in turn supported by baille plug 2S. This support element 45 is, if desired composed of two elements identified by reference numerals 45a in Figure 4. Disposed within the orifice holder 31 is a removable orifice 32 as shown. This removable orifice 32 is held in position in the orifice holder by a snap ring 50 and an O-ring 49 is provided intermediate the orifice 32 and the orifice lholder 31 to prevent leakage of fluid therebetween. The exterior bevelled surface of the orifice holder 31 is also provided with an O-ring 48 to prevent leakage between the orifice holder and the baille plug 25 when the orifice 32 is in operation. Holes 35 are provided in the baille plug 25, as shown, for use in threading the plug into place when a threaded plug is used. An O-ring 52 is provided, as shown, for providing a seal between the baille plug and the casing segment. A pair of holes 51, best seen in Figure 5, are provided in the baffle plug 25 for accommodation of rods 37 (Figure 3). An O-ring 47 is provided in a groove around rods 37 to prevent fluid leakage. To hold rods 37 in place during such time when the check valve is not in operation there is provided a shear pin 39 the positioning of which can best be seen in Figure 5. These pins, as shown, pass through the body of the baille plug and through corresponding openings in the rods 37. These pins are made of a shearable material such as brass. Two small bolts 40 are shown inserted into each rod 37 and these bolts are intended to be positioned immediately below the lower surface of the baille plug 25 to prevent fluid back pressure from forcing the valve actuating mechanism upward after the shear pin has been sheared off and the valve put into operation. Collapsible sleeves made of thin aluminum, brass, pewter, Woods metal, plastic material, or other suitably collapsible material (as sleeve 107 of Figure 7) or compression springs 39a (Figure 12) surround the upper portions of rods 37 to prevent the rods from moving downward before it is desired to actuate the valve. The upper ends of rods 37 are provided with threaded openings 38 and the bottoms are also provided with threaded openings, or bolt holes 41. A ring 26 or circular plate is bolted by bolts 44 to rods 37. Plate 26 is also provided with openings 34 inline with openings 35 of the baille plug. A flapper valve 27 is attached to supports 45 by a spring loaded pivot 28. In its open position valve 27 is held downward by an element 42 which (see Figure 4) is a semicircular element. Element 42 is attached at either endby bolts .43 to the bottom threaded portions 41 of rods 37.

When the apparatus of Figure 1 is used as a section of the casing threads 22 and 23 on the ends of the casing segment are provided for attaching to well casing. If this valve actuating mechanism is to be used in conjunction with a shoe, the shoe `element 24' can be made integral with the bottom of the casing segment 21 or it can be attached thereto with a threaded collar, not shown.

To make the embodiment illustrated in Figure 1 corn- .4 plete with all mechanism necessary for operation of the valve a cementing plug 33 is shown just above the ring 26.

Concentrically disposed within the ring plate 26 is a circular opening 53 which is intended to be larger in diameter than the diameter of the port 29 in the baille plug 2S so that when drilling mud or cement slurry is pressured downward, the plate 26 will not be forced downward thereby inadvertently placing the check valve 27 into operation. Shear pin 39 is made sufllciently large that its shear resistance is greater than any possible fluid pressure drop across plate opening 53.

In Figure 6 is illustrated another embodiment of my check valve assembly in which a casing segment is identifie'd by reference numeral 76. In this casing segment is positioned a baille plug 77. This baille plug can be threaded to the casing segment, as illustrated in Figure l, or if the plug is metal it can be welded in place or if it is a solid resinous or plastic material it can be cast in place. rPhe baille plug 77 is provided with a port 83 the lower bevelled portion of which is intended to accommodate a pivotally mounted orifice holder 91 which swings into and out of the cylindrical port 83 of plug 77 around the same pivot as a spring loaded ilapper valve 88. Disposed within this holder 91 is an orifice 92 which is held in place by a snap ring 94. O-rings 93 and 97 are provided for making this assembly fluid-tight. A rod 85 is illustrated as being disposed vertically through the bale plug 77. To prevent this rod 85 from moving downward until such time as it is desired to operate the valve there is provided a shear pin 86 through the rod and extending outward therefrom in such a manner that the pin and its rod are supported by the top surface of the baille plug. O-ring 96 is provided for sealing rod 85 and is held in place by a gland 95. Attached to the bottom end of rod 85 or made integral therewith is a wedge 87 so disposed that its sharp edge points downward. The shear pin 86 prevents rod 85 and plate 79 from moving downward inadvertently while the wedge 87 prevents the rod from moving upward. Mounted as shown is a spring loaded flapper valve 88. This flapper valve 88 is so arranged that when placed into operation it rotates around its pivot and seats against the lower bevel surface of the orifice 92. A valve holder arm 90 is held against the lower portion of valve 88 by a spring S9. This spring 89, however, can be replaced by a cord or wire provided they are breakable for release of the valve when it is desired to place same in operation. The plate 79 is bolted to the top end of rod 35, as illustrated, fand one or more dummy rods 80 are provided for supporting the plate. When rods 80 are used they do not extend through the entire length of the baille plug 77 but only extend into the plug a short distance. Rods 80 are held in position by shear pins S1 and these shear pins are intended to be sheared oil at the same time shear pin 86 is sheared to allow plate 79 and rod 85 to move downward to release 'valve 88. A cementing plug '78 is illustrated immediately above plate 79 and it is intended that when fluid pressure above plug 78 is sufficiently greater than the pressure below the plug, the plug forces plate 79 with attached parts downward to release the valve 88. An opening 84 in plate 79 is larger in diameter than the diameter of port 83 in the baille plug so that fluid flow downward will not inadvertently release the valve 83 into its operating position.

VShear pins 81 and 86 are madel sufficiently large that their shear resistance is greater than any possible force due to pressure drop of fluid passing through Vthe plate opening 84. r

In Figure 7 a casing segment 101 is providedwith a baille plug 103 which is attached to a casing in any suitable manner desired, as explained above relative to Figures l and 6. The baille plug 103 is provided with a port 110, the lower section of which is bevelled to accommodate an orifice holder 115. This orifice holder is provided with an orifice 116 of desired diameter and O-ring 123 is provided therebetween to prevent leakage. An O-ring 122 is provided in the outer surface of the bevelled portion of the orifice holder 115 while a snap ring 125 holds the orice in place in its holder. The orifice holder is pivoted by a spring loaded pivot 117. A circular plate 104 having an opening 109 in its center is disposed above the top surface of the baffle plug 103. A rod 105 is attached to plate 104 as shown and extends through the bafe plug and terminates in the form of a valve ball holder 111. The lower surface of this holder 111 is so formed as to at least approximately iit the surface of a valve ball 112 which is intended to be held against a retainer or holder element 113. To hold the rod 105 in its proper position is provided a collapsible sleeve 106 surrounding the upper portion of the rod. This sleeve rests against the bottom surface of an opening 119 in the upper portion of the plug 103 and the upper end of the sleeve supports at least in part plate 104. One or more dummy rods 108 which are provided with collapsible sleeves 107 are provided, as shown, for maintaining the plate in substantially a horizontal position. The lower end of sleeves 107 are supported by the bottom ends of openings 120 in the top portion of the plug 103. An O-ring 118 is provided around rod 105 to prevent leakage. Rods 114 and 124 are attached to the walls of the casing segment to prevent the valve ball 112 from dropping downward after the ball is released fromV its holding elements. Element 1,21 is a bottom extension of baille plug 103` and is shaped as shown to funnel the valve ball to its seat when released.

A cementing plug 102 is illustrated in position against the top surface of Jthe circular plate 104 before such time that pressure on the cementing plug 102 would cause downward movement of the plate 104.

In Figure 8 is illustrated still another embodiment of my invention in which reference numeral 151 identifies the casing segment into which is rigidly positioned a baiiie plug 153. This bathe plug has a port 154 which is provided with an orifice holder 155 with O-ring seal 157. An orifice 156 is held in position in the oriiice holder by a snap ring 159. An O-ring 158 seals against leakage between the orifice andthe orifice holder. The orice holder is pivoted by a spring loaded pivot 160 in such manner that downward flow of liquid through port 154 can rotate the orifice in its holder out of the port while upward flow of liquid therethrough will rotate the orifice holder and orifice into the port 154 to restrict'iiow of liquid therethrough. Attached to the underside of the bale plug 153 is a spring loaded hinged valve 161 more or less similar to that illustrated in Figures l and 6. This hinged valve 161 is held in an inoperative position by a cord or Wire 172 which is broken upon release of the valve for seating.

The valve releasing mechanism in this embodiment is somewhat different in actual structural detail than the release mechanisms hereinbefore described but the principle of operation is substantially the same. In Figure 8 a. cylinder 162 is attached to the wall of the casing segment 151. A piston 165 is provided in the portion of the cylinder adjacent the casing segment l151. The movement of piston 165 is limited by the presence of a partition 164 so that the piston will not be ejected from the cylinder. On the side of the partition 164 opposite piston 165 isfanother piston 163. Pistons 163, 165 and partition 164 are provided with O-ring seals 16351, 165a and 16451, respectively, to prevent leakage of fluid. This valve releasing piston-cylinder assembly is powered by Huid pressure acting on thel side of piston 165 opposite piston 163. Fluid acting on piston 165 moves this piston from right to left and pushes rod 167 forcing the hinged valve 161 away from its retained position thereby breaking cord or wire 172 and allowing the spring loaded pivot 160 to rotate the valve into its closed position. Fluid pressure acting on the right hand side of piston 165 enters this cylinder through a port 171, conduit 170 and port 169 from the 6 During the manufacture or assembly of this apparatus the wire or cord 172 is attached to the cylinder 162 or if desired the wire or cord can be attached to the Wall of casing segment 151 by providing a hook or eye thereon. The cord or wire is then fastened to the-valve 161; In normal circulation of drilling fluid in a well equipped with the apparatus of Figure 8, the fluid pressure on the right hand side of piston 165 is nearly balanced by the uid pressure on the left hand side of piston 163 so that under normal conditions this piston assembly does not move. The unbalance in pressure is not suiiicient to break the cord or wire 172. However, in order to prevent accidental movement of this piston assembly the portion of the cylinder chamber 166 intermediate partition 164 and piston 165 is tilled with a compressible fluid such as air n or gas to assist in holding the piston assembly at the right hand end of its extent of movement.

The embodiment of my invention illustrated in Figure l0 is similar in some detail to that illustrated in Figure S but dilers therefrom in the use of a valve ball as the valve in place of a hinged dapper valve. In Figure 10 a casing segment 201 is provided with a baflle plug 205 having a port 204 extending axially therethrough. In the bottom end of port 204 is provided a hinged orice holder 206 and orifice 207. A snap ring 208 holds the orifice in position in the orifice holder while O-rings 209 and 210 provide necessary seals. The orifice holder 206 rotates around a spring loaded pivot 211m such a manner that when liquid flows' downward through port 204 this hinged assembly is moved downward to permit unrestricted How of liquid while upward flow is restricted by the orifice 207. A conduit 213 is provided along the outer surface of the casing segment with ports or openings 212 and 2 14 as shown. Liquid pressure from the space above acementing plug 202 is pressured through port 212 along channel 213 and through port 214 against the side of a piston 215 adjacent port 214. A pusher element 217 is attached to the piston as shown in such a manner that as a piston is moved from right to left pusher 217 moves ball 221 from the position indicated in the drawing. An O-ring seal 216 'is provided around piston 215 to prevent leakage of fluid in either direction. Tomake certain that piston 215 does not inadvertently operate to release ball 221 a compression spring 218 is provided as shown. The upper portion of the cylinder wall 220 in combination with a spring loaded hinged element 219 holds ball 221 in. an open valve position until such time that the piston releases the ball. Rods 222 and 223 are positioned across the casing segment below this valve mechanism so that ball 221 cannot fall down the casing and become inoperative as a Y check valve.

In Figure 9 is illustrated a portion of the apparatus of Figures 8 and l0 with an extra element 173 provided. This element 173 is merely a plug provided with an O- ring seal 174 in such a manner that only the volume of liquid in conduit-170 can enter cylinder 162 of Figure 8 or cylinder 220 of Figure l0 and likewise only this same `volume is all of the liquid which can llow upward into the main body of liquid above plugs 152 and 202. This plug element 173 is not absolutely necessary but it is preferred that such a plug be used as a safety element in caseV of breakage of cylinder 162 or cylinder 220. In case .0f breakage of either of these cylinders, without plug 173 liquidcould bypass the check valve apparatus in either direction when the cementing plug is below ports 169 and 212..

The volume of conduit 170 from the plug 173 to piston in cylinder 162 in Figure'S or to piston 215 in cylinder 220 in Figure l0 is filled with liquid during assembly of the apparatus because, if filledwith air, and pressure is appliedto plug 173 the air is `merely compressed and; will not move the piston 165 vof Figure 8 orkmain body of liquid 168 above the cementing plug 152. '75

the, the piston 215 of Figure l0 to free the valve of the rejective mechanism.

In the operation of the apparatus of my invention with special reference to Figure l this check valve fapparatus is attached either as a casing segment between .-two sections of casing near the bottom end thereof or on the bottom of the casing before running of the casing. When this apparatus is installed on the casing the well is full of drilling mud and the casing running operation is started by lowering the casing with this check valve assembly into the well. The drilling mud enters the casing from the bottom and its entrance is restricted somewhat by the presence of the orifice 32 so that the casing does not fill too rapidly. When the orifice 32 has a predetermined diameter to admit drilling mud at a predetermined rate a section of casing is usually filled with mud by the time it is lowered sufficiently to add another section of casing. This running operation is Athus carried out until such time that the bottom end of lthe casing string reaches the bottom of the well. After this running operation is complete and when it is desired to cement the casing, cement is pumped into the casing until a desired volume of cement slurry is added after which a cement follow-plug is inserted into the casing. Drilling mud is pressured into the casing behind the plug such as plug 33 in Figure 1. Upon continued pumping of drilling mud behind the plug the cement slurry Areaches my check valve apparatus and flows through opening 53 in plate 26 and through port 29 in the baille plug 25. Since such a cement slurry has a considerable carrying power its passage downward through port 29 tends to unseat the orifice and its holder from the bevel vsection 30 and the slurry can therefore ow downward through port 29 in a more or less unrestricted manner. When the cementing plug 33 reaches my check valve assembly and touches the top surface of the plate 26 the plug pushes this plate downward and shears oif pins 39 `the mud as the cement sets between the casing and the walls of the well. When the check valve and the oriiice lbecome seated the cement slurry cannot flow upward through port 29 and all fluid below batlle plug 25 in the casing and the cement slurry in the annulus between the casing and the walls of the well is maintained stationary so that setting of the cement can take place.

After this cementing operation has been completed the drilling mud is pumped out of the casing and the casing can be perforated at any level from which it is desired to produce oil or gas.

After cementing a section of casing in a well, under Ysome conditions it is desired to drill the well still deeper using a smaller diameter drill bit. Under this latter condition it is desirable to construct all of the parts ofA my check valve assembly, including the valve, orifice 'memben and baie plug, etc., of materials which can be drilled out. Among such materials are moldable resinous or plastic materials, cast iron, cement, aluminum alloy,

Imagnesium, and the like, either singly or in combination. Cast iron can be used as a drillable material because it is quite brittle.

In the operation of the apparatus embodiments of Figures 6 and 7 the check valves are placed into operation when cementing plugs 78 or 102 reach the top 'surface of Iplates 79 and 104, respectively, and force these plates'with theirv attached elements downward. In Figfiire 6 plug, 78 pushes platek 79, rod 85 and wedge 87 zdownward to release ilapper "valve 88 and its spring loaded hinge causes the valve to seat against the bevelled surface of orice 92. In Figure 7 the downward movewalls of the well.

ment of plate 104 and rod 105`causes element 111 to force the ball 112 downward and this operation breaks support element 113 to free the ball so that it can either rise in the cement slurry or be carried upward by the back ow of a small volume of slurry to seat against the bevelled surface of orilice 116.

in the embodiments illustrated in Figures 8 and 9 when the cementing follow-plug 152 is seated against the top surface of baille plug 153 a pressure diiferential is immediately effected between the liquid 168 above the cementing plug and the liquid below the cementing plug under which condition liquid pressure is transmitted through port 169 down the conduit 170 and through port 171 to the port side of piston 165. This piston is then moved from right to left with the breaking of the cord or wire 172 to release the hinged dapper valve 161. In the embodiment of Figure 10 liquid pressure transmitted from conduit 213 through port 214 moves piston 215 from right to left to force the ball 221 from its retained position for seating against the bevelled surface of oriiice 207.

As mentioned hereinabove in case of breakage of cylinder 162 of Figure 8 or cylinder 220 of Figure l0 with the presence of plug element 173 in conduit 170 of Figure 8 or in conduit 213 of Figure l0 by-passing the Huid around my check valve assembly is prevented.

In case a cementing operation is carried out by a Z-plug method the apparatus shown in Figure l1 illustrates such an operation. Reference numeral 251 identities a casing segment in which is disposed a baffle plug 255 having a port 258 through which cement slurry and mud can be pumped. The casing is run in a manner similar to that described in relation to Figure 1. When the casing is landed and it is decided to cement the casing a rst cementing plug 253 is inserted into the casing at the head of the well. This rst cementing plug which may be called a leading plug, is provided with a centrally positioned breakable section in such a manner that when the plug is seated against an object this breakage section can be ruptured by uid pressure to permit flow of fluid through this plug. Such a plug (leading plug) is used in cementing operations to wipe the casing clean of mud ahead of the cement slurry and also to eliminate any tendency for mixing of the slurry and mud as the mud is being forced down the casing. When a sufficient amount of slurry has been added a cementing followplug 252 is introduced into the casing and drilling mud pumped into the casing behind this plug. Upon continued pumping of mud behind plug 252 it is forced down the casing and wipes the walls clean of slurry and prevents mixing of the slurry and mud. As the two plugs with a slug of cement slurry between them are forced down the casing, plug 253 is, of course, the first to seat against plate 254. When this plug is seated against plate 254 it forces this plate with attached parts downward to release the valve for seating purposes. As mud is pumped into the casinghead suicient pressure is exerted against diaphragm 257 of the leading plug and the diaphragm breaks allowing the cement slurry toow downward through port 258 and out the bottom of the casing and up the annulus between the casing and the the leadingplug 253 a mud pump pressure increase can be observed by the operator. Upon release of this pressure cement slurry tends to flow backward through port 258 and raise either a apper valve similar to valve 27 of Figure 1 or a ball valve similar to ball 112 of Figure 7 ltoseat against the valve seat and prevent back flow of slurry. As soon as the valve has been seated the mud pump pressure can be released.

While certain embodiments of my invention have been described for illustrative purposes the invention obviously is not limited thereto.

I claim:

` l. A deep well choke and check valve assembly com- When the follow-plug 252 reaches prising, in combination, a housing member, `a baiiie plug in and supported 4by said housing member, aportextending through said plug for flow -of uid, said port having an upper portion and a lower portion, an orifice, a pivoted orifice holder, said orifice holder being adapted to rotate said orice into said lower portion of said port to restrict ilow of fluid upwardly only 4in said housing member, a check valve assembly supported within and by said housing member and 'below ,the Ilower portion of said port, said check valve assembly -being adapted to check upward iluid flow in said housing member, said check valve assembly comprising a seat and 5a valve head operable to close against said seat, the end portion of said orifice adjacent said valve head being said seat, a check Valve release mechanism extending from a level above the upper portion of said port to said check valve, and said release mechanism being adapted to release said check valve for seating upon pressuring a cementing plug down said housing member to a level below the aforesaid level.

2. A device of the character described comprising a casing having a bore, a -baille plug in and supported by said casing, a port extending through .said plug for flow of fluid, said port having an upper portion and a lower portion, an orifice, a pivoted orifice holder, said orifice holder being adapted to rotate said orifice into said lower portion of said port to restrict flow of fluid upwardly only in said casing, the lower portion of said orifice being a beveled valve seat, a check valve disposed in said bore below said seat and being adapted to be ,moved 'to close said seat by upward ow o'f iluid in said bore, a check valve latch disposed to restrain said check valve from taking said seat, a check valve latch release mechanism extending from a level above the upper portion of said baffle plug to said check valve latch and said release mechanism being adapted to release said latch to free said valve for seating upon pressuring a cementing plug down said casing to a level below the aforesaid level.

3. A device of the character described .comprising a well casing, a baille plug secured to the inner wall of said casing and having a port for the passage of fluid, a valve seat disposed in said casing below said port .and being adapted to be moved to said port to restrict upward flow of fluid therethrough, a check valve disposed in said casing below said seat, said Acheck valve being adapted to close said seat to check upward tlowof fluid in said casing, a check valve holder disposed .to hold .said check valve inoperative, a cementing plug movable in said vcasing above said hae plug, means for releasing -said vcheck valve, one portion .of said means being yabove said bale plug, another portion extending from said one portion through said bathe plug for releasing said valve, said means for releasing said valve being adapted to operate said holding mechanism to release said check valve upon pressuring said cementing plug into pressured relation with the portion of said means for releasing said valve above said baille plug.

4. A device of the character described comprising a casing having a bore, an annular valve seat secured to said casing in said bore to control flow of fluid therethrough, a check valve disposed in said bore below said seat and adapted to be moved tol close said seat by upward flow of fluid in said bore, a latch disposed to restrain said check valve from taking said seat, a cementing plug movable in said bore above said seat, and a release extending from a level above said valve seat to said check Valve for releasing same to seat, said release operating to release said check valve upon pressuring said cementing plug into pressured relation with the portion of said release extending above said valve seat to check upward flow of fluid in said casing.

5. A deep well casing choke and valve assembly comprising, in combination, a housing member having a conduit therethrough, means to attach said housing member to a well casing, a bale plug in said housing, a port extending 10 through said plug for flow of fluid, said port having an upper portion and a lower portion, an orifice, `a pivoted orice holder, said orifice holder being adapted to rotate said orice into said lower portion of said port to restrict flo-w of iluid upwardly only in said conduit, a check valve in said housing ybelow said bai-lle plug, a check valve holder, a check valve holder release, said check valve being held inoperative by said `holder and said release casing, a baffle Vplug rigidly attached to the inner wall of said housing member, said baffle plughaving an upper surface and a lower surface, a port extending axially through said baffle plug, said port having an upper .por- 'tion and a lower portion, an orifice, an orifice holder, said holder being adapted to hold the said orifice, a spring loaded hinge pivoting said orifice holder, said orifice holder and hinge being adapted to position said orifice in said port, said orifice being adapted to restrict upward` flow of iiuid through said port and to permit unrestricted downward flow of fluid therethrough, an annular valve seating surface 'being provided on the downward facing side of said orifice, a check valve, said check valve being adapted to seat against said annular valve seating surface and means to release said vcheck valve, said means l to release said check valve comprising a movable ring disposed generally acrosssaid housing member above said baffle plug, the inner diameter of said ring being greater than the diameter of said port in said baille plug, a valve `rod disposed vertically `throughsaid bame plug, said Valve rod having an upper end and a lower end, means to hold the upper yend of said valve rod above the upper surface of `said baffle plug to maintain `.at leasta portion of said ring above and out of contact with said baffle plug, the lower end of said rod extending below the lower surface of said baffle plug, a valve holding means and disposed to hold said 'check valve in an open position with respect to said seating surface when the upper end of said valve rod is positioned above the upper surface of said-'baffle plug, and said checkvalve being adapted to close against said seating surface upon pressuring a cementing plug into pressured relation with said ring whereby said ring, said valve rod and said valve holding means being pressured downward thereby releasing said valve.

9. ln the apparatus of claim 8 a valve releasing element being attached to the lower end of said valve rod, said valve rod being so positioned in said baffle plug as to be intermediate said valve and the wall of said housing member, said means to release said check valve being a downwardly pointing wedge and being adapted to release said valve from said holding means upon said pressuring of said cementing plug downwardly against said ring thereby forcing said wedge downward and releasing said valve.

l0. The apparatus of claim 8 wherein said Valve is a bal-l, said valve holding means is a frangible support on the wall of said housing member, said means to release said valve being a block attached to the Ilower end of said valve rod, the lower surface of said block being concave upward in such a manner as to coincide substantially with the upper surface of said ball, said valvelbeing in an inoperative position between said frangible support and said block, said frangible support being adapted to break and thereby release said valve ball upon said pressuring of said cementing plug against said ring whereby said ring, valve rod and block are forced downward.

1l. lA deep well casing choke and check valve assembly comprising, in combination, an elongated housing member, means to attach said housing member to a well casing, a bale plug rigidly attached to lthe inner surface of said housing member, said baille plug having an upper surface and a lower surface, a port extending axially through said baille plug, said port having an upper portion and a lower portion, an orifice, an orifice holder, said holder holding said oriiice, a spring loaded hinge pivoting said orifice holder, said oriiice holder and hinge being adapted to bias said orifice in said port to restrict upward ilow of iluid through said port and being adapted to peimit rotation against said bias to permit unrestricted downward ilow of tluid therethrough, a valve seating surface on the downward side of said orifice, a check valve, a spring loaded pivot biasing said check valve closed against said oriiice to check upward iluid ilow and means to hold said check valve in an open position and to release said check valve for its closure against said seating surface, comprising, a ring disposed generally across said housing member above said baille plug, a valve rod having an upper end and a lower end disposed vertically through said baille plug, means to hold the rapper end of said rod above the upper surface of said baille plug to maintain at least a portion of said ring above and out of contact with said baille plug, the lower end of said rod extending below the lower surface of said baille plug, said means to hold said check valve in an open position and to release same comprising a valve retainer element attached to the lower end of said valve rod and being disposed to hold said check valve open against the bias of said spring loaded hinge and to release said valve upon pressuring a cementing plug into pressure relation with said ring.

12. The assembly of claim 1l wherein said means to hold the upper end of esaid rod above the upper surface of the baille plug is a shear pin extending through said rod into said baille plug.

13. A deep well casing choke and check valve assembly comprising, in combination, an elongated housing member, means to attach said housing member to a well casing, a baffle plug rigidly attached to the inner surface of said housing member, said baille plug having an upper surface and a -lower surface, a port extending axially through said baille plug, said port having an upper portion and a lower portion, an oriiice, an oriiice holder, said oriiice being disposed in said oriiice holder, a spring loaded hinge pivoting said oriiice holder, said spring loaded hinge biasing said orifice into the flower portion ofsaid port to restrict upward ilow of fluid through said port and being adapted .to permit rotation against lsaid bias to permit unrestricted downward ilow of lluid through said port, an annular valve seating surface on the downward facing side 12 of said orifice, a check valve, a spring loaded hinge biasing said check valve closed against said seating surface to check upward ilow'of iluid and means to hold said check valve open against said bias and to release same comprising a ring disposed generally across said housing member above said baille plug, a pair of valve rods disposed vertically through the body of said baille plug, said valve rods having upper ends and lower ends, means to hold the upper ends of said valve rods above the surface of said baille plug, said ring being attached to the upper end of said valve rods, the lower ends of said valve rods extending below the lower surface of said baille plug, a valve retainer being attached to the lower ends of said valve rods, said valve retainer being adapted to hold said check valve open against said bias and out of contact with said valve seating surface and to release said check valve upon pressuring a cementing plug into pressured relation with said ring.

14. The assembly of claim 13 wherein said means to hold the upper ends of said valve rods above the surface of said baille plug is a separatek shear pin extending through each valve rod into said baille plug.

15. A device of the character described comprising a well casing, a baille plug secured to the inner wall of said casing and having a port for the passage of fluid, a valve seat disposed in said casing below said port and being adapted to be moved toward said port to restrict upward ilow of uid therethrough, a check valve disposed in said casing below said seat, said check valve being adapted to close said seat to check upward flow of iluid in said casing, a check valve holder restraining said check valve from seating against said seat, a cementing plug movable in said casing above said baille plug, means for releasing said check valve extending from a level above said baille plug to a level adjacent said check valve, said means operating to release said check valve upon pressuring said cementing plug into pressure relation with said means for releasing said check valve.

References Cited in the le of this patent UNITED STATES PATENTS 2,197,396 Mairies u Apr. 16, 1940 2,217,708 Scaramucci Oct. l5, 1940 2,320,670 Scaramucci .lune 1, 1943 2,646,125 Hall July 2l, 1953 2,662,602 Schnitter Dec. 1S, 1953 2,713,914 Kriegel July 26, 1955 2,751,021 Muse June 19, 1956 2,812,820 Nelson Nov. 12, 1957 2,848,053 Curry Aug. 19, 1958 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 2,907,392 October 6, 1959 lGeorge S. Ormsby It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and` that the said Letters Patent should readas corrected below.

Signed and sealed this 17th day of May 1960.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Ofcer v Commissioner Of Patents 

